Suppression of pollution in mineral fiber manufacture

Abstract

Methods and apparatuses for separating heat hardenable constituents from an aqueous solution of thermohardenable fiber binder material by insolubilizing the constituents through the application of both heat and pressure are disclosed.

We claim: 
     
       1. A batchwise method for separating heat hardenable constituents from an aqueous solution of thermohardenable fiber binder material which method comprises insolubilizing said constituents by heating said constituents in treatment equipment comprising a batch treatment vessel having means for heating the interior of a batch of solution and means for cooling the walls of the vessel during said heating, said aqueous solution being heated to a temperature between about 150° C. and about 240° C., at an absolute pressure of from about 6 to about 40 bars, effecting said cooling by preheating the aqueous solution to be treated by bringing it into heat exchange relation with the vessel wall during said insolubilization, and thereafter separating the insolubilized constituents from the water of said batch. 
     
     
       2. A continuous method for separating heat hardenable constituents from an aqueous solution of thermohardenable fiber binder material which method comprises insolubilizing said constituents by heating said constituents in a system comprising a heat exchanger, a continuous flow heater, and a continuous flow reactor, preheating the aqueous solution to be treated by passing it through said heat exchanger, heating said preheated solution in said continuous flow heater to a temperature between about 150° C. and about 240° C. and at a pressure from about 6 to about 40 bars, by the injection of steam, effecting insolubilization of said heated water by passing it through said reactor, cooling said solution by returning it to said heat exchanger, and thereafter separating the insolubilized constituents from the water. 
     
     
       3. Apparatus for separating heat hardenable resin constituents from an aqueous solution thereof, comprising pressurized treatment equipment for heating the solution to a temperature sufficient to insolubilize said constituents and for maintaining the solution heated and under superatmospheric pressure for a time sufficient to effect such insolubilization, said treatment equipment comprising a batch treatment vessel having steam injection means operatably connected to a source of steam for heating the interior of a batch of the solution therein and having means for cooling the walls of the vessel during said heating, said pressurized treating equipment having an inlet for receiving pressurized solution to be treated and having an outlet for discharge of treated solution at atmospheric pressure, a supply source for solution to be treated, means connecting the supply source with said inlet including cooling surfaces for effecting heat exchange with the outer boundary of the batch in said vessel, thereby preheating the solution being supplied, and means receiving the treated solution discharged from said outlet and for separating the insolubilized constitutents from the heat treated solution at atmospheric pressure. 
     
     
       4. Apparatus as defined in claim 3 in which the cooling means comprises a jacket for the vessel and means for circulating solution to be treated through said jacket prior to being introduced into the treatment vessel. 
     
     
       5. Apparatus as defined in claim 4 in which the cooling jacket through which the solution supply circulates encloses only a part of the treatment vessel, and a second cooling jacket enclosing another part of the treatment vessel, and separate coolant circulation means associated with said second jacket.